Santa Claus. He's rather like the parent we eventually shipped off the the old folks' home after we became tired of all the loud and annoying antics. But that's not how it should be! Discovering the flaws of your loved ones should bring you together, not tear you apart — at least that's the message of Aardman Animations' Arthur Christmas. And the film's star, James McAvoy, is here to tell us why Santa Claus doesn't care about you (and why that's OK).

I saw Arthur Christmas and it made me cry (a lot), so thanks for that.

James McAvoy: It made me cry too!

What was it about the Arthur Christmas script that made you want to get involved?

All really, really good Christmas movies (I think) have one thing in common. And that is, [the notion that] the whole idea and the whole ethos of Christmas is in danger. Something is wrong with Christmas. Either Santa Claus is in physical danger, or some kid doesn't believe or is in danger of not believing, or perhaps the presents won't be delivered. Basically something is threatening what it is that Christmas is.

In this movie, the thing that threatens Christmas is that its integrity seems to be compromised by a business-like nature. And the fact that one kid not receiving a present doesn't seem to be that big a deal to Father Christmas. You might as well just get rid of the whole thing, and I liked that. I really liked that because I felt that it reflects what's going on today. Don't get me wrong, it's just a piece of entertainment for the family, but it also reflects what's going on in the world. The marketing of it all, and the financial side of it all, is that all so much more important than what is basically making sure that people are happy? And giving and generosity and all the great stuff the comes from Christmas. And that's kind of what the film is about. Plus you get all the comedy and the action and all that as well.

The humor is very adult at times, what's your favorite funny moment in it all?

I think my favorite joke is when I say, "Grand-Santa this is impossible, it can't be done." And he says, "Well, they used to say it was impossible to teach women to read." That's quite adult humor there, and quite irreverent and slightly risque humor as well. Someone's going to be offended by that, even though it's not meant in an offensive way. I just like that in a movie, I think it's slightly brave. Some of the jokes are slapstick and physical but a lot of the jokes aren't patronizing children. They're quite linguistically funny. That's something that I think we miss a lot in kid's movies.

All of the characters have these giant flaws in their characters. Were you comfortable giving the House of Claus such great flaws?

Yeah definitely. It's got to reflect something in real life, and nobody's family is perfect. But this guy [Arthur] thinks his family is perfect. He thinks they're amazing and he thinks his father is the greatest person on Earth and that Christmas is perfect, that Christmas is the best thing ever. But neither of those things really live up to his expectations. That's something I think a lot of children are going to have to face at some point. It's about seeing what your parents actually are, and seeing what Christmas actually is. Seeing that it's not as holy and perfect as you maybe once imagined, but still seeing the worth in it and loving it. Maybe even forcing the rest of the world around you to come up to your expectations...

Sometimes your parents let you down. It's quite a strong and sophisticated topic to get into really for a Christmas kids movie. His Big Brother and his Father all let him down. They're all desperately flawed and it's just about realizing that your parents aren't perfect but that doesn't make them any less deserving of your love, or your family. Maybe it makes them even more deserving of your love and it makes that bond more vital.

What were most surprised after seeing Arthur on the big screen?

I found it surprising just how much I laughed and how much I cried. Equal measure. I really did cry a lot, I found it very moving. That was the big surprise. I knew it was meant to be funny and moving but you never knew it was going to work. I was laughing my ass off and crying my ass off.

What are your favorite holiday movies?

I love Polar Express. When I was growing up, I really liked the Santa Claus movie with Dudley Moore.

What was your favorite update to the Kringle Enterprise in this film?

The present distributor the one that you stick in a sock, that can load a sock in 2 seconds flat. The Elves they're whole military Matrix-style elf operation was probably the best part for me.